Exam hack:

Given condition : Two vertices of GG are adjacent if and only if the **corresponding sets intersect** in exactly two elements.

Take an example A = {1,2,3,4,5,6}. Total subsets possible = 2^6 = 64.

Now we have degree 0 means nodes can be <=1 as with 1 node also no intersection possible.

- 0 node : only 1 subset possible {} ==>1
- 1 node : only 1 subset possible {1}, {2}, {3}, {4}, {5}, {6}. ==>n. Hence , ans is 0 node + 1 node =
**n+1 option (C)**